The sheetrock/stud walls have a resonant frequency determined by stud spacing, depth, and height.
The resonant frequency in my home studio control room using 2x6 studs on 16" center, 8' height was near 16Hz.
When subjected to enough sustained LF, the walls resonant frequency can be excited, resulting in enough movement to cause rattles, or even more serious effects like GM noted.
I wouldn't commit to a subwoofer location without testing it first.
They can, but the "breathing" noise may be perceived from the small hole's location. The
After spending much of the day looking at Ricci's measurement of the SVS PB13, and examining SVS current models excursion/output potential vs. cost and cabinet size, I'd be inclined to use them in room rather than "piping in" the output of a monster size sub.
Art
Sturdy house, well my entire house is designed as brick and block - which is basically concrete ceilings and brick+concrete walls. It's pretty far from flimsy, but I would note that my bass needs are perhaps less hardcore than many people here aim for. For me, in a way, the DTS10 approach (or the IB one!) is mostly 'because it's reasonably doable while you're building your house')
But even with sturdy walls I imagine rattling glass is a real possibility.
GM- ha I even reached out to that CT seller just out of curiosity, but shipping to UK is a hassle.
But even with sturdy walls I imagine rattling glass is a real possibility.
GM- ha I even reached out to that CT seller just out of curiosity, but shipping to UK is a hassle.
Ha, indeed. And at some point too much power is worrisome. Funnily enough my current subs "naively" seem more powerful - 2x SVS SB13U - 1000W each, 13.5" drivers (vs Danley's 12" x 2) .
Fair, but for me the challenge is that I'm bound by livingroom practicalities. I can't just move stuff around without huge black blocks being in the way of actually living. So they will likely have to be where they are designed to be, and DSP them into submission if possible.
Even moreso with both IB and "Danley in-wall" - you have to design first, test later.. leap of faith?
Do you know any rough formula to determine if a hole is too small? I'm thinking a 5x5 inch (13 x 13cm) hole..
My current 2 alternatives to the Danley are:
1/ Arendal 1723-2V - White - 50.0W x 71.2H x 60.9D cm - 2399 - CEA12.5hz: 104
2/ Rythmik G25HP - Black - 45(W) x 60 (H )x 65(D) with grille
Both reach down to 15-odd Hz. Cheaper too than the DTS10..
Big leap of faith for an empiricist like me 😉.
Don't know any rough formulas, but the hole will have big time band-pass results as well as chuffing, measured in meters per second.
The Hornresp simulator could probably approximate both.
Here is what happens to the response of the Keystone sub, a tapped horn with a keystone shaped exit, when it's mouth is restricted progressively (10meter distance outdoor measurement) :
Fb is driven lower with each mouth size restriction resulting in slightly more low frequency output, while upper in band response takes a huge hit.
Air noise from reducing the mouth opening to a fist size probably won't be the big problem.💩
Art
Wow I never saw this response, missed notification. Thanks @weltersys - I note that the upper response suffers but the lower isn't too bad under 150hz.
One big problem though, how would I "connect" the mouth of the DTS10 to the hole in the wall. I'm currently imagining effectively having the sub freestanding in the office with the output port close to the hole in the wall, building a bit of wood around it (aka building it into a cupboard) but I could never match the holes exactly, for one there'd always be a little space between the box and the wall.
Would some foam style material suffice? Or how would you create a short (1cm or so?) duct between sub output and wall hole?
One big problem though, how would I "connect" the mouth of the DTS10 to the hole in the wall. I'm currently imagining effectively having the sub freestanding in the office with the output port close to the hole in the wall, building a bit of wood around it (aka building it into a cupboard) but I could never match the holes exactly, for one there'd always be a little space between the box and the wall.
Would some foam style material suffice? Or how would you create a short (1cm or so?) duct between sub output and wall hole?
Nema 4x door gasket or similar can handle the pressure long term and comes in varying widths, thicknesses.
A -6 to -9dB loss (a huge hit) on all but a 1/6th octave point at the lower impedance/excursion minima is very bad.
I'm thinking piping the exit of a TH through a 5x5 inch (13 x 13cm) hole may throw away 75-90% of it's output except for a narrow band peak at Fb. I'm thinking 2x SVS SB13U will put out more LF than a DTS-10 piped through a (perfectly sealed) 5" x5" duct.
Anything short of an "L" bracket gasket seal may leak as more sound into the office than the home theater room.
Art
Ah apologies I had updated my assumptions to a much larger hole, e.g. 14"x18" - the full size of the DTS10 output.
I just need to aesthetically hide it, is a white speaker grille/cloth allowed or will that impact sound deeply?
Would you happen to have some drawing on this? searching google comes up with nothing helpful (too many car parts to count..)
Nema gasket material normally comes with the appropriate sticky tape on one side; don't recommend any other type fasteners to degrade its performance. 4x is explosion proof for mining or similar, so if wanting to remove it will take a suitable solvent assuming nothing of interest spec-wise has changed since I last dealt with such in '94. Cut/assemble as a picture frame.
Hmm, my problem is that I'd have to screw one side of the gasket into the wall, over the unmovable wall-hole. Of course I have some freedom as to where to put said hole, but even then, lining it up on the other side with the DTS10 sounds very tough given its design
I don't think I can easily fit a gasket end over this and then line it up perfectly....
I would use two gaskets, one to fit the horn, the other somewhat wider stuck to the wall/whatever, I guess in essence making a version of Art's 'L' gasket once firmly pressed together. Having done extensive UL/CSA testing, any sort of hardware going through the gasket is a bad plan long term, but we weren't allowed to try stapling, so maybe an option.
Speaker grille cloth won't affect the sound.
If you are not reducing the horn's output size, going through a well sealed stud wall should not have much effect on the output.
Use a strip of 3/4" wide x 1/2" thick self-adhesive neoprene foam weather stripping around the 18.89" x 14.26" horn exit ("exhaust port").
Push the cabinet tight enough against the wall to compress the weather strip.
Then screw "L" brackets or wood blocks to the floor on three sides of the cabinet to prevent it from moving to keep the seal air-tight long term.
Art
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